Wireline Operated Dump Bailer And Method For Unloading Of Material In A Well

Abstract

This invention relates to a dump bailer (1) for insertion into a well (20) in the ground. The dump bailer (1) includes a receptacle (2) which communicates with surroundings through an inlet (4) and an outlet (6), and a pump (10) positioned in a flow path (7) between the inlet (4) and the outlet (6). The pump (10) is positioned at the outlet (6), and the pump (10) during transport of the dump bailer (1) in the well (20) constitutes a sealed barrier for the carried material (18) in the receptacle (2). A method for use of the dump bailer (1) is also described.

Claims

1. Dump bailer (1) for insertion in a well (20) in the ground, the dump bailer (1) comprises: a receptacle (2) which communicates with surroundings through an inlet (4) and an outlet (6) and a pump (10) positioned in a flow path (7) between the inlet (4) and the outlet (6); the pump (10) is positioned at the outlet (6), and the pump (10) during transport of the dump bailer (1) in the well (20) constitutes a tight barrier for a carried material (18) in the receptacle (2).

2. The dump bailer (1) according to claim 1, wherein the outlet (6) is at a leading end portion (8) of the dump bailer (1).

3. The dump bailer (1) according to claim 1, wherein the receptacle (2) is provided with an axially displaceable piston (16) in the flow path (7).

4. The dump bailer (1) according to claim 1, wherein the dump bailer (1) is provided with a rotary motor (12).

5. The dump bailer (1) according to claim 1, wherein the pump (10) is constituted by a mono pump.

6. The dump bailer (1) according to claim 4, wherein the pump (10) is driven by the rotary motor (12) via an axle (14).

7. The dump bailer (1) according to claim 1, wherein the dump bailer (1) is coupled to a wireline tractor (19).

8. The dump bailer (1) according to claim 1, wherein the dump bailer (1) at its outlet (6) is provided a first releasable barrier (22).

9. The dump bailer (1) according to claim 8, wherein the dump bailer (1) at its outlet (6) is provided with a second releasable barrier (26).

10. The dump bailer (1) according to claim 9, wherein the second barrier (26) is provided with an opening (28) which is releasably and communicatively connected to the outlet (6).

11. The dump bailer (1) according to claim 10, wherein the opening (28) is provided with a valve (30).

12. Method for unloading a material (18) in a well (20) in the ground by the use of a dump bailer (1) according to claim 1, the method comprises the following steps: unloading the material (18) in the receptacle (2) through the outlet (6) of the dump bailer (1): letting the unloaded material (18) flow along an outer side of the dump bailer (1); and letting the unloaded material (18) flow into the receptacle (2) through the inlet (4).

13. Method according to claim 12, wherein the unloaded material (18) is circulated for a desired amount of time through a flow path (7) on the outer side of the dump bailer (1) and back to the flow path (7).

14. Method according to claim 12, wherein the material (18) comprises a detergent chemical.

15. Method according to claim 12, wherein the material (18) comprises a lubricating chemical.

16. Method according to claim 12, wherein the material (18) comprises a hydrate dissolving chemical.

Description

[0051] In the following are described examples of preferred embodiments illustrated in the accompanying drawings, wherein:

[0052] FIG. 1A shows a principle sketch of a dump bailer according to the invention;

[0053] FIG. 1B shows the dump bailer of FIG. 1A arranged in a well and wherein carried material is being pumped out;

[0054] FIG. 2A shows the dump bailer of FIG. 1A in an embodiment wherein a first barrier is arranged at an outlet;

[0055] FIG. 2B shows the dump bailer of FIG. 2A arranged in a well wherein the first barrier is released from the dump bailer and wherein the carried material is being pumped out;

[0056] FIG. 3A shows the dump bailer of FIG. 2A in an embodiment wherein a second barrier is arranged at the outlet;

[0057] FIG. 3B shows the dump bailer of FIG. 3A arranged in a well and wherein the first barrier is released from the dump bailer and wherein the carried material is being pumped out through an opening in the second barrier;

[0058] FIG. 4A shows the dump bailer in an alternative embodiment, and wherein a first barrier is arranged at the outlet;

[0059] FIG. 4B shows the dump bailer of FIG. 4A arranged in a well and wherein the first barrier is released from the dump bailer and the carried material is being pumped out; and

[0060] FIG. 5 shows the dump bailer of FIG. 1A in an embodiment without an upper piston.

[0061] On the figures the reference numeral 1 denotes a dump bailer according to the invention. The dump bailer 1 preferably comprises a cylindrical receptacle 2 which typically also constitutes the load-bearing main element of the dump bailer 1. The receptacle 2 is provided with an inlet 4 and an outlet 6 which communicatively connects the receptacle 2 and the surroundings. The inlet 4, the receptacle 2 and the outlet 6 constitute a flow path 7 through the dump bailer 1. The outlet 6 is most preferably located at the leading end portion 8 of the dump bailer 1, and may have any suitable shape.

[0062] A pump 10, here shown in the form of a mono pump, is arranged by the outlet 6 and driven by a rotary motor 12 via an axle 14. The inlet 4 is positioned between the rotary motor 12 and the pump 10.

[0063] A piston 16 is sealingly displaceable in the receptacle 2 and along the axle 14. The piston 16 may be left out when there is little risk that the material 18 in the receptacle 2 will mix with the surrounding liquid as shown in FIG. 5. The piston 16 is positioned in the flow path 7 between the inlet 4 and the outlet 6.

[0064] The dump bailer 1 is typically displaced in the well 20 by means of a not shown wireline, but may also be coupled to a wireline tractor 19.

[0065] When the dump bailer 1 is at the desired location in a well 20, the rotary motor 12 is started whereby the pump 10 starts and pumps material 18 out through the outlet 6. An under-pressure then forms in the receptacle 2 and surrounding liquid which flows in through the inlet 4 displaces the piston towards the pump 10 until the receptacle 2 is emptied and the material 18 has flowed into the well 20.

[0066] In FIG. 2A an embodiment is shown where the dump bailer 1 at the outlet 6 is provided with a first barrier 22. The first barrier 22 is arranged to form a barrier between the well 20 and the material 18 which is pumped from the dump bailer 1.

[0067] The first barrier 22 may generally be of the “umbrella-type” which is arranged to open towards a wall 24 of the well when it is displaced out from the outlet 6, see FIG. 2B.

[0068] FIG. 3A shows an embodiment wherein there is also arranged a second barrier 26 between the outlet 6 and the first barrier 22. In this embodiment the second barrier 26 is telescopically coupled to the outlet 6 via an opening 28. The material 18 may thereby flow through the opening 28 and in between the first barrier 22 and the second barrier 26 after that the second barrier 26 has been brought into a sealing position against the wall 24 of the well as shown in FIG. 3B. The first barrier 22 and the second barrier 26 are displaced axially and relative to each other during pumping in of the material 18 between them.

[0069] A valve 30, here in the form of a check valve, prevents the material 18 from flowing out through the opening 28 after that the dump bailer 1 is displaced away from the second barrier 26.

[0070] The piston 16 is left out when the material 18 in the receptacle 2 is going to be circulated out through the opening 6 and back to the receptacle 2 through the inlet 4. This embodiment is shown in FIG. 5.

[0071] In an alternative embodiment which is shown in FIG. 4A, the pump 10 is arranged close to the rotary motor 12. A release valve 32, here shown in the form of a rupture disc 33 in a first floating piston 34, prevents the material 18 from flowing out of the outlet 6. The material 18 is close to the pump 10 limited by a second floating piston 16. The pressure in the material 18 is in balance with the surrounding pressure.

[0072] When the rotary motor 12 is started and drives the pump 10, surrounding liquid flows through the inlet 4 and the pump 10. The first floating piston 34 abuts against the shoulder 36 at the end portion 8. The pressure in the material 18 in the receptacle 2 increases until the release valve 32 opens, typically by breaking of the rupture disc 33. The material 18 thereafter flows through the outlet 6 and into the well 20.

[0073] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.